This invention relates to apparatus, systems and methods for the real time or near real time detection of data connection losses, particularly those experienced in the access network of a telecommunications network. Such detection allows for remedial action to be taken swiftly. This is especially so if the fault causing the connection loss can be identified to be of a type allowing for personnel already at suitable locations in the network to work on the faults before they leave the locations. In a specific exemplary implementation, such identifiable faults include those caused by an “intervening act” in the access network.
The terms “intervening act” or “interventions” herein refer to activities by parties such as telecommunications engineer or similar personnel despatched by a telecommunications company to work on intervention point plant and nodes located in the access network such as distribution points (DPs) or cross-connection points such as primary cross-connection points (CCPs/PCPs). In the conduct of such work (e.g. to install a new service, or to carry out repairs), the engineer's activities may inadvertently cause a fault to another line(s) at the worksite, such as the DP or PCP in question or in any case, in the same part of the network as the line that is being worked upon. In the experience of the applicant, a perhaps-surprisingly high number of such “intervention faults” are generated on a regular basis. Some of these faults may cause the gradual degradation of the affected customer's connection, while many others are “instant breaks” caused by e.g. dislodgment of the affected link from a terminal block in a DP cabinet. Instant breaks result in the immediate loss of data connection to the customer concerned, i.e. even while the engineer or operative is still at the worksite. The scale of intervention faults generated can be considerable, especially where there is much activity in the access network e.g. when and where a fibre to the cabinet (FTTC) service is being provisioned.
Ideally, the engineer would know immediately when he causes an intervention fault. The reality however, is that this is often difficult or even impossible in view of the enormous number of cables crowded into a tightly-packed cabinets and other plant located in the open environment in variable weather conditions. Telecommunications companies typically do not detect and repair intervention faults in real time before the engineer leaves the site: conventionally, they first learn of the problem when a customer makes a complaint, which even in the case of instant breaks, are usually made after the engineer has left the site. At that stage, a second engineer call-out has to be made to the site to repair the intervention fault caused during the first engineer visit. As might be expected, each engineer visit has a cost associated with it, and this repetition of visits is wasteful of time and other resources. Perhaps more importantly, there is a negative impact on customer relations as the required repairs are seldom immediately carried out, but instead scheduled in the usual way in a queue so that the affected link may be down for hours if not days or more. In this way, a potentially simple repair which the engineer might have been able to attend to during the first attendance might spiral into a significant period of service outage, customer dissatisfaction and unnecessary cost for the service provider.
It would be desirable for intervention faults to be repaired without being customer complaint-driven, in a way which minimises service disruption and doing away with the need for a subsequent engineer visit.
The present invention accordingly provides, in a first aspect, a method of detecting loss of data connection in a plurality of links between an exchange and one or more of a plurality of network terminals arising during presence of a user at an intervention point node on the links between the exchange and the network terminals, comprising: receiving connection information about a loss of data connection on any one of the links; receiving duration information about a duration of the user presence at the intervention point node; determining if the loss of data connection occurred within the user presence duration; causing line tests to be conducted on each of the links for which loss of data connection is determined to have occurred within the user presence duration; receiving results of the line tests including a number of links being determined, by the line test, to exhibit a fault; and determining if the number of links determined to exhibit a fault exceeds a predetermined threshold number.
Preferably the connection information comprises an instantaneous or near instantaneous report about loss of data connection on any one of the links.
Preferably the connection information comprises a loss of synchronisation alarm received from a multiplexer or access node in the exchange via an element management system.
Preferably, receiving connection information comprises failure to receive a signal indicative of a restoration of the connection.
Preferably the duration information takes the form of user presence start and stop times received from the user while at the intervention node point.
Preferably the method further comprises sending, to the user, information about the affected links, wherein the information includes the identity of the affected links if the number of affected links falls below the predetermined threshold number.
Preferably the method further comprises sending information to a cable theft alert system if the number of affected links exceeds the predetermined threshold number.
Preferably the loss of data connection in links between an exchange and one or more of a plurality of network terminals arises as a result of user activity at the intervention point node.
The present invention accordingly provides, in a second aspect, an apparatus for detecting loss of data connection in links between an exchange and one or more of a plurality of network terminals arising during presence of a user at an intervention point node on the links between the exchange and the network terminals, comprising a processor arranged to: receive connection information about a loss of data connection on any one of the links; receive duration information about a duration of the user presence at the intervention point node; determine if the loss of data connection occurred within the user presence duration; cause line tests to be conducted on each of the links for which loss of data connection is determined to have occurred within the user presence duration; receive results of the line tests including a number of links being determined, by the line test, to exhibit a fault; and determine if the number of links determined to exhibit a fault exceeds a predetermined threshold number.
Preferably the intervention point node comprises a distribution point or a cross-connection point in a telecommunications network.
Preferably the processor is arranged to receive connection information in the form of a loss of synchronisation alarm from a multiplexer or an access node located in the exchange.
The present invention accordingly provides, in a third aspect, a system for identifying loss of data connection in links between an exchange and one or more of a plurality of network terminals arising during presence of a user at an intervention point node on the links between the exchange and the one or more network terminals, comprising: an apparatus for detecting loss of data connection as described above; an element management system by which the apparatus receives connection information; a communications device by which the apparatus receives duration information; and a line test system.
Preferably the system further includes a cable theft alert system.
The present invention accordingly provides, in a fourth aspect, an access network comprising a system as described above and further comprising: an exchange; a multiplexer or an access node located at the exchange; a plurality of network terminals; and an intervention point node located on the links between each of the plurality of network terminals and the exchange.
The present invention seeks to identify in real- or near real-time, those connection losses in a network which are capable of repair at the work location where a user or engineer is already present. As there are many different causes of faulty data links however, not all faults on the line passing through the intervention point node (e.g. a DP or a CCP/PCP) where the engineer is present at a given time, are necessarily capable of being remedied. For example, the fault on the line could lie upstream or downstream of the engineer's location within the network. To remove or reduce the chances of wrongly identifying a fault as one which can be worked on by the present engineer, implementations of the method involve an analysis of time and place data to generate an “engineer-centric” view of the status of the links in question, which includes a test which helps generate a profile of the possible cause of the faulty line(s).
Connection information that at least one of the lines running through the DP or PCP is suffering from connection loss (which may include quality degradation) is initially obtained. In preferred implementations, this connection information provides an almost instantaneous snapshot of the status of the links, preferably in the form of loss of sync alarms. The system checks if this connection loss occurred during the time when the engineer was present at the DP, PCP or such other intervention point. If it was, that line determined to be faulty is line-tested. The number of such faulty lines passing through the intervention point node is collated, and compared against a pre-determined threshold number. Where the number of lost connections exceeds the threshold number, it may be deemed that the problem is something which the engineer cannot address e.g. an instance of cable theft (in which typically a large number of cables are simultaneously cut). A more likely profile of fault(s) of the kind which can be repaired at the DP or PCP is one in which the actual number of faulty links lies below the threshold number, indicating e.g. intervention faults caused by earlier provisioning or repair activity. The threshold number is selected according to the telecommunications company's own policies, historical data or like, as being indicative of what is thought to be indicative of a larger problem like an event of cable theft.
Preferably, connection information about faulty lines takes the form of loss of synchronisation alarms received from a DSLAM or MSAN located in the exchange via an element management system. As will be explained further below, the two relevant types of loss of synchronisation messages respectively indicate that connection has been lost, and that the connection has been regained or restored. In a preferred implementation, information about the loss of connection comprises failure to receive a signal indicating that connection has been restored after the link is known to have gone down.
In a preferred application, the user or engineer signals his presence at the intervention point by stating “start” and “stop” times which may include the times he started and stopped activity at the node. In response, the system will eventually respond to the engineer at the worksite with a message which includes information about those links identified to have a fault of a nature capable of being repaired. If there are no faulty lines, a null list of directory numbers is sent. This may also the case if the number of faulty links exceeds the pre-determined threshold (as the engineer is unable to repair such faults), although some other indication may be sent. In both cases, the engineer will typically close the job and leave the site. It is only if the faulty lines are identified to be of a nature capable of repair, that the response message to the engineer will include a list of those links needing repair, allowing for work to commence on those identified line.